The present invention relates to bulk loaded liquid propellant guns of a type wherein a liquid propellant is injected into the chamber of the gun between the projectile and the bolt. Method and apparatus are provided for use in liquid propellant guns such as that described assignee's prior application, Ser. No. 612,817 filed Sept. 12, 1975, now U.S. Pat. No. 3,992,976.
Many prior art devices have, of course, used liquid and gas mixtures to form an explosive or propellant. U.S. Pat. No. 424,119 uses a small amount of gasoline with compressed air and U.S. Pat. No. 3,567,103 uses a fuel and a gas which will fire by compression. In contrast to this type of weapon, however, the bulk loaded liquid propellant gun effort has concentrated on the injection of a liquid or liquids into the propellant chamber in ways designed to eliminate as much as possible any space between the bolt and the projectile. Any introduction of air was accidental or incidental and was, therefore, uncontrolled. It has been found that a gun which fills the entire space between the bolt and the projectile with a liquid propellant is prone to catastrophic pressure increases and uncontrolled burning. A prior art liquid propellant gun uses this detonation by compression as a means for initiating combustion of the propellant as shown in U.S. Pat. No. 2,947,221. Accordingly, present research has centered upon ways of decreasing peal pressure and producing uniform burning of propellants.
Some prior art guns utilize hypergolic propellants injected into a large chamber while others ignite a stream of propellant injected in to a chamber such as that in U.S. Pat. No. 4,037,995. The invention is applicable to bulk loaded liquid propellant guns which inject a propellant into a space between a bolt and projectile then ignite the propellant after the completion of the injection cycle.